Antenna system



Aug. 3@, H949. I w M TE 2,480,155

ANTENNA SYSTEM Filed Feb. 28, 1945 Patented Aug. 30, 1949 UNITE-In 7 v 1i2,40,155 ANTENNA SYSTEM Robert wa t L Radio Corporation of America, a corporation of llelati are :Application February 2 9Cl'aiiiis.

This inventionrelatesto antennas and-hasior its principal object the :provision of irnproyed feed means for dipoleantennas of the sheet radiator :type, 'such as those described in; topnding U. *S, patent applications Ser., NQ. 574,898 and Ser. No.-574,899, filed January 27,1945, by Robert W. Masters and entitled Antenna.

In 'orderto feed adipole antenna from a-coaxial ime or other unsymmetrical circuit, itis necessary to provide some kind of balance-con- Version means in :the "connection between 'the idipole and 'the feed "means. Various systems of balance conversion, are Well known in the prior art, and it is deemed unnecessary to describe any iof 'them herein-exceptto point out that all of them :require someistru-cture in addition to the main feed linean'd the antenna itselfpand that in -substantially every *case this; structure includes reactive elements Which limit the band width t-hroughout which the system will operate eiliciently.

One system in which the need for, a separate -convertor structure is eliminated is described in copending-U. "S. application Ser. No. 579 983, filed February 27, 1945; now U; S. Patent No 2,433,183 issued December 23,;1947, to LesterJ. Wolf'and '{entitle'd Antennas. The present invention is an improvement upon that of said Wolf application.

The invention will be described with reference tot a any n aw pf whi h th r l figure is a me sr ain l tes 9 ediee antenna of the sheet radiator type embodying my myed e i tem-r. e a

A preferred embodiment of the antennas described in said "application Ser. No. 574,899 is illustrated comprising a pairpf sheet radiators land I, each including'as'ubstan allyrectilinear edge 3 and 3' respectively. Therectilinear'edges 3 and 3' are-each of the order'of one half wavelength long at the operating frequency. Inthe presentcase, each sheet element comprisesf'a' plu- 'Y'allity 'of rod or"tube"members*spaced fr'ornl'fea'ch :{other by a small fraction 10f "afwavelenjglth, fso that electrically each r'adiatoracts as a continu- 's' t.

The radiators I and l are "supportdupon a d'dnductive mastibybrackets '1, at the i'ipperand lower ends ofth'e vedges t an"d 3'. :In addition to supporting the radiator elements, the brackets "5150 "senate, grena ine upper and pat ents of the edges 3 and? 't'o the mast 5. "The radiators l and I are to be fed at points 9 and 9' on their respective longitudinal edges 3 and 3. Although the points 9 and 9' are the midpoints of the edges 3 and 3' in the present illustration, other points s, rare-serial:Na eson'ao wit-5019a alongsaid edges may 'be fed instead topr ovide a ad fie nt n mpeda e. in he lmq e mventional rtypes'of dipole structure, the twoieed points-mustbeenergized -l80; degre'es out oi phase with each; other ;In,accordance with priorgart, t s WQUId b c omplish d by runn n twcl ne d n e m t 5 rpmz t es f e QQi l Ja l to adine:balance convertor, ,or possibly by providing a'eonyertor inthe mast, betweentheradiabo s-V. n her ev n ,thea rementiq edd advantages of dine balance convertors would have to be borne v H t-.a itdan ewit -myin en ion them nfie d l n ll s 15 h. ..m :1 9 th l weri r cke ft of one of the radiators, for. example-the radiator I. The opter conductor oi: ;the line l5 may be co ecte to1 sa .=b ec s t 1, e the, me f rommhep n ll, the ne 5. d q cd a nei ensu a e. 0 h ad ate! 1'1 9 -ih -;mi rah-where t u r cqqnd qfwt e 112 I5 is connected to the radiator I. 'Ifhe outer o duc 9f th .8215 m y be generated a o o nt -9 the rad ator. J n rm diate th points If! and B' althOugh thiS is not necessary mt ner t 9nhflth :s st m-, 7 l V v .The d ere nduc oref h r e l.tim yestsnd "b y nd the qini 'jebout s elfWey..w,, ie gf dr int 9- The ns 2 us tq i.t ev l ne. i sc rm te ztfo the d a r. Lame e d P se .9- l.. in th veratie .fi he; st m the ert o vi th u era e du r q nib t ne ilti g e' i n t P01 1. Q a d. sxac ee it. .,.-We e. a ,ti i "9 the radia e? it s il atiHe a e im n is present d.be w enl hep i 1, nd ef ri appears between the point 9 and ground. th rqlia ea re st e ine IE. qiy d e' e l i :tw n hexediete' s I q iee t 'e $1 afi'tfina tx a fit'in lee "be as? b d .v "ates-lenses we ges a i 1 ar 5 necte d together by the meansi' i; to p rtvias neutral poi tsw chare at gr uncl potential. Thetef m ,f t e id doi'e ias u ed h e is i h edt include slichl neutral points at th same 5 potential fas g'ro'u'rid ambush not connected tQ flYlihftiQ. a. A v The inventi e has fl been described as an m:- fproved feed system for d "ole antennas of the 4 J 1,. I l my sheet radiator, of 50 10 cc co ve ture is tatf'qulrea. *nss'aiy derivation is obtained by placing the feed line along the surface of one of the radiator elements so that the normal impedance of the radiator appears be- M tween the end of the outer conductor and ground.

The outer conductor is connected to one of the radiator elements and the inner conductor is connected to the other. Although the invention has been illustrated as embodied in a particular type of sheet structure, it will be apparent without further description that the invention may be applied equally well to other types of sheet radiator dipoles, or any dipole structure wherein each of the radiator elements is grounded at at least one point and fed at another point.

I claim as my invention:

1. A radio antenna including at least one pair of radiator elements each having at least one ground point and a feed point, a coaxial line with its inner conductor connected to the feed point of the first of said radiator elements and its outer conductor connected to the feed point of the second of said radiator elements, said line lying against said second radiator element between its said feed point and its said ground point.

2. A radio antenna including a pair of sheet radiator elements with respective feed points to be fed 180 degrees out of phase with each other, a coaxial line having its inner conductor connected to the first of said elements and its outer conductor connected to the second of said elements, said line being conductively connected to said second radiator element between said feed point and one end of said second radiator element.

3. A radio antenna including at least one pair of radiator elements, each having at least one grounded point and one feed point, and means for feeding said radiator elements 180 degrees out of phase with each other, comprising a coaxial line with its outer conductor connected to one of said ground points and to one of said feed points, with said line lying against the surface of the corresponding radiator element between said points of connection, the inner conductor of said line being connected to said feed point of said other radiator element.

4. A radio antenna including at least one pair of radiator elements, each of said elements having at least one substantially rectilinear edge, means for supporting said elements with said respective rectilinear edges approximately parallel and adjacent one another, a coaxial line extending generally along said supporting means to one end of the said rectilinear edge of one of said elements, thence substantially along the surface of said last-mentioned element to a point on said rectilinear edge thereof, with its outer conductor connected to said point and its inner conductor connected to the corresponding point of said other element.

5. A radio antenna including at least one pair of coplanar flat sheet radiator elements, each of said elements having at least one substantially rectilinear longitudinal edge, means for supporting said elements with said respective rectilinear edges approximately parallel and adjacent one another, a coaxial line extending generally along said supporting means to one end of the said rectilinear edge of one of said elements, thence substantially along the surface of said last-mentioned element to a point on said rectilinear edge thereof, with its outer conductor connected to said point and its inner conductor connected to the corresponding point of said other element.

6. A radio antenna including at least one pair of coplanar fiat sheet radiator elements, each of said elements having at least one substantially rectilinear longitudinal edge, conductive means for supporting said elements with said respective rectilinear edges parallel and adjacent one another, a coxial line extending generally along said supporting means to one end of the said rectilinear edge of one of said elements, thence substantially along the surface of said last-mentioned element to the midpoint of said rectilinear edge thereof, with its outer conductor connected to said midpoint and its inner conductor connected to the corresponding point of said other element.

7. An antenna including a pair of sheet radiator elements, said elements being supported upon conductive supporting means by at least one short conductive connection to said supporting means, said radiator elements each having a feed point, said feed points being remote from said conductive connection, a coaxial transmission line having an inner conductor connected to one of said feed points and an outer shell connected to the other of said feed points, said transmission line lying along one of said radiators from said other feed point to said conductive connection.

8. An antenna including a pair of radiator elements, each of said elements being supported on conductive supporting means by at least one conductive connection to said supporting means, said radiator elements each having a feed point, said feed points being remote from said conductive connections, a coaxial transmission line having an inner conductor connected to one of said feed points and an outer shell connected to another of said feed points, said transmission line lying along one of said radiators from said other feed point to said conductive connection and along said conductive connection to said supporting means.

9. An antenna system including a number of radiating elements having feed points closely adjacent, a conductive supporting means for said radiating elements, conductive connections from said supporting means to said radiating elements at voltage nodal points on said radiating elements, a two conductor transmission line having one conductor connected to each of said feed points, said transmission line lying along one of said radiators from its feed point to said conductive connection and along said conductive connection to said supporting means.

ROBERT W. MASTERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,960,006 Hagen May 22, 1934 2,153,298 Cork Apr. 4, 1939 2,160,053 Barbour May 30, 1939 2,313,513 Brown Mar. 9, 1943 2,321,454 Brown June 8, 1943 2,433,183 Wolf Dec. 23, 1947 OTHER REFERENCES Dual Rocket Antenna Characteristics, by G. Hendrickson, Radio, July 1946, pp. 14-15. 

